Melanie Abbott probes the activities of undercover police officers.
How is Woolwich in south-east London coping with the killing of drummer Lee Rigby?
Is A&E in England on the verge of collapse? Simon Cox investigates.
Can the criminal justice system deliver on its promise to deal with historic sexual abuse?
An assessment of Police and Crime Commissioners' performance six months into the job.
How high rates of autism among some immigrant groups are still affecting the uptake of MMR
Simon Cox investigates the virtual currency Bitcoin. What is it and what is it for?
Who can parents trust to tell them where is best for their children to have heart surgery?
Mark Dowd travels to Argentina to probe the background of the new Pope.
Simon Cox travels to Cyprus to examine how the banks ended up in such a mess.